Sunlight shines through a grove of redwood trees at the Muir Woods National Monument in Marin County in Northern California. Eric Risberg/AP hide caption

itoggle caption Eric Risberg/AP

Marine scientist Walter Boynton of the University of Maryland Center for Environmental Science is studying mud, ooze, and other material from the Chesapeake Bay's bottom to find out what areas are healthy and where it's dying. John Poole/NPR hide caption

itoggle caption John Poole/NPR

An aggressive encounter between two male greater prairie chickens (Tympanuchus cupido). During aggressive encounters, males leap into the air and strike their opponent with feet, wings and/or beak. Fort Pierre National Grassland, South Dakota. Gerrit Vyn/gerritvynphoto.com hide caption

itoggle caption Gerrit Vyn/gerritvynphoto.com

A stunning golden tapestry woven from spider silk is unveiled at the American Museum of Natural History in New York City after four years of work — and the help of more than 1 million spiders. R. Mickens/AMNH hide caption

itoggle caption R. Mickens/AMNH

A smallmouth bass caught on a lake near Ely, Minn. One-third of smallmouths surveyed by the USGS showed signs of intersex. Sam Cook hide caption

itoggle caption Sam Cook

Julie Feinstein, collection manager of frozen tissue lab at AMNH, removes a rack of samples from one of the liquid nitrogen-cooled storage vats. She's wearing special gloves so that, as she puts it, she doesn't stay attached to the vat. R. Mickens/AMNH hide caption

itoggle caption R. Mickens/AMNH

A farmer plants soybeans in an untilled field. No-till farming, in which crops are planted into last year's field stubble without plowing, has gained acceptance in the past two decades as a way to build organic matter, reduce erosion and control pesticides and fertilizers. J.D. Pooley/AP hide caption

itoggle caption J.D. Pooley/AP

The coats of domestic dogs vary wildly and can be long, short, straight, wavy, curly or more. Pictured here (left to right) are three breeds with different coat types: Saluki, Vizsla and Samoyed. Tyrone Spady hide caption

itoggle caption Tyrone Spady